The statements in this section merely provide background information regarding an apparatus for circulating balls and may not constitute the related art.
Rust, foreign substances, and the like are accumulated in a pipe line in which a fluid such as water flows as time passes, and thus when the rust, foreign substances, and the like are left, the inside of the pipe line is gradually narrowed to cause a problem that an apparatus or a system is not normally operated.
In order to solve such a problem, recently, techniques of injecting a large number of cleaning balls into a pipe line to be circulated inside the pipe line so as to remove scale accumulated in the pipe line have been applied.
For example, the pipe line may comprise a plurality of tubes arranged in a heat exchanger of a powder plant. The heat exchanger of the powder plant is configured to have plural tubes and is an apparatus which cools water for power generation using sea water or fresh water, and an equipment for cleaning the tubes is referred to as a cleaning equipment.
For cleaning the tubes, elastic cleaning balls are injected into a water box of a condenser in which cooling water flows. Then the cleaning balls are evenly dispersed in the water box and flow into each tube, so as to clean the inside of the tubes.
The cleaning balls thus passing through the tubes are separated from the cooling water by a strainer at an outlet, pass through a ball recirculation pump (hereinafter, simply referred to as a “pump”) and a ball collector again, and then are re-injected into an inlet of the water box through a ball injection nozzle so that continuous tube cleaning is possible.
When an appropriate number of balls are circulated, the condenser tube is kept clean and the thermal conductivity of the tube is maintained in good condition and thus the performance of the condenser or the heat exchanger can be ensured.
Therefore, it is necessary to check whether or not an appropriate number of balls are circulated through the cleaning equipment.
The related art adopts, as a measure of the degree of the cleaning state, a method of checking the collection rate of cleaning balls, that is, how many balls are collected with respect to the number of balls injected into a circulation path. For example, when 1000 cleaning balls are injected into a circulation path, circulated, and then collected, if the number of balls collected is 950, it is determined that better cleaning is carried out compared to a case where 900 balls are collected.
However, in the related art, only the number of balls circulated in the circulation path is considered and thus a problem arise in that whether the balls perform an efficient and effective role of cleaning tubes cannot be actually assessed.
This is because some of the balls are not circulated due to swirl or trapping or loss of the balls caused by the structure of the circulation path and the internal shape of the circulation path, and due to these balls, it is meaningless to consider only the number of circulating balls for evaluating the degree of cleaning.
The related art has a problem in that in the above-described example, if 50 to 100 balls are not normally circulated or lost, it is assumed that 900 to 950 balls are normally circulated and if 900 balls sufficiently perform a role of cleaning the tubes while being circulated in the circulation path, there is no reason for evaluating that cleaning is poor compared to a case where 950 balls are circulated.
On the other hand, the cleaning equipment adopts a counter as means for checking whether or not an appropriate number of balls are circulated through the cleaning equipment. The counter is a device for counting the number of cleaning balls circulating inside the circulation path.
A conventional counter (Korean Patent Publication No. 10-2005-0008214) has a structure in which a transparent passage pipe is arranged in the middle of a circulation path and a sensor is arranged on the outside of the passage pipe and emits infrared rays to detect balls flowing inside the passage pipe and count the number of the balls.
However, in the conventional structure, since balls are aggregated and pass together through the passage pipe, many balls may be counted as one by being detected at the same time and thus there is a problem of erroneous counting of the number of the cleaning balls.